event rewards!!!!!

[ayet]

i want to understand why every time i play big bang lvl 4 effect event i get only one blind skill capacity, is that normal?? how i can get lvl 4 big bang with just one blind effect capacity??
i have to wait one month to get one big bang an at the end i don't really get it, i have to play 2 times the same event to get just one big bang
.

 

[Slik]

I did not receive any Blind Skills in previous Skill chest raid but I received three Blind Skills in this raid. It just varies. You can upgrade level 3 skills to level 4 if you have the dice.